In one conventional form of erecting buildings, each of the floors thereof may be formed of concrete by forming the individual floors at ground level and then raising the formed floor to the desired elevated level by suitable jacking apparatus. Such a method of constructing a building is illustrated in U.S. Pat. No. 2,686,420 of Philip N. Youtz. In the Youtz patent, the concrete floors are raised by means of tension screws or threaded lifting rods. Means are provided on the upper ends of support columns for acting on the screws and raising them. In one form, the lifting means is a center hole hydraulic jack which is mounted on the column so that the tension screw extends through the center of the jack. The lifting operation requires that the holding nut be turned down on the screws after each successive lifting step with the operation being repeated over and over again to effect the desired complete lifting of the slab.
Donald J. Bentley et al show, in U.S. Pat. No. 2,830,788, a pushing and pulling apparatus utilizing means for exerting a frictional grip on a caisson to hold it against movement in one direction while the caisson is being moved stepwise in the other direction. A fluid-operated gripper ring is provided for making temporary frictional engagement with the caisson. Pistons and cylinders are provided extending between the load and the gripper ring and are pivotally connected thereto to provide the desired powered operation of the apparatus.
In U.S. Pat. No. 2,920,870, George E. Suderow shows a system of jacking having manual controls effective to maintain a platform level during raising thereof on a plurality of supporting legs. The device utilizes a hydraulic control system wherein the jacking mechanisms for all of the legs of the device can be operated in unison.
Samuel Goldberg shows, in U.S. Pat. No. 3,065,573, a building construction wherein the floor slabs are raised with a uniform master lift pressure throughout the hydraulic system.
Bernard Ahl shows, in U.S. Pat. No. 3,325,146, a mold raising mechanism utilizing eccentrically mounted grabs including upper and lower grab heads connected to two independently operated extensible and contractible pressure fluid actuators for raising and lowering the grab heads selectively. One of the grab heads may be provided with releasable means to prevent an associated grab from clamping an associated climbing pole.
In U.S. Pat. No. 3,948,483, Jean Gonzagues de Leaumont shows a sliding shuttering raising device wherein the sliding shutterings are moved along a slide bar by means of jacks. The device includes means for preventing unintended backward movement.
In U.S. Pat. No. 3,973,885, Hans Schmidt shows an apparatus for constructing a wall including hydraulic jacks adapted to climb a vertically extending jack tube. The apparatus includes a formwork support structure, at least one pair of inner and outer formwork sections suspended from the support structure and at least one of which is adapted to move toward and away from the other. A jack means is provided for supporting the formwork support structure on a lower foundation or completed wall section and is arranged to lift the formwork support structure.